rust-nalgebra-sparse 0.12.0-1 is ready for sponsorship.

This packages nalgebra-sparse for the raygeo dependency chain.

Feature/dependency notes:
 * The package currently ships the default library surface only.
 * Optional upstream features compare, io, proptest-support, and
   serde-serialize are disabled in a Debian patch.
 * The compare feature needs matrixcompare-core and the upstream tests need
   matrixcompare; those crates are not currently packaged in Debian.
 * The immediate raygeo dependency only needs nalgebra-sparse itself, not these
   optional feature packages.

Test notes:
 * Generated autopkgtests are marked flaky via debcargo.toml because the
   upstream test suite depends on unavailable matrixcompare support.
 * ./build.sh nalgebra-sparse completed successfully on amd64.
 * Raw autopkgtest summary reports the generated tests as FLAKY because the
   tests require disabled proptest-support, compare, and io features; the raw
   log still says "I: Autopkgtest run was successful."
 * debcargo-conf reports UNKNOWN while analyzing the autopkgtest log; this is
   expected for the intentionally flaky generated tests.

Lintian:
 * lintian --display-info --pedantic was run on
   rust-nalgebra-sparse_0.12.0-1_amd64.changes.
 * Remaining tags are the expected initial-upload/distribution tags before
   sponsor finalization plus usual Rust crate informational/pedantic tags.
